Adjustable chair



FIG. 1 is a top view of an adjustable chair showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a back view thereof;

FIG. 6 is a front isometric view thereof.

The ornamental design for an adjustable chair, substantially as shownand described.